DE112012001940T5 - Composite of conductive polymer and porous carbon material and electrode material using the same - Google Patents

Abstract

The purpose of the present invention is to provide an electric double layer capacitor, a lithium-ion secondary battery and a lithium-ion capacitor each having excellent cycle characteristics; an electrode material from which the electric double layer capacitor, the lithium-ion secondary battery and the lithium-ion capacitor can be obtained; and a composite material used in the electrode material. The composite material of the present invention is a composite material prepared by composing 0.5 to 5 parts by mass of a nitrogen atom-containing conductive polymer per 100 parts by mass of a porous carbon material. The composite material of the present invention is a composite material in which the peak area ratio (nitrogen / carbon ratio) of the peak area of nitrogen atoms to the peak area of carbon atoms in the spectrum measured by X-ray photoelectron spectroscopy is 0.005 to 0.05.

Description

Technical area

The present invention relates to a composite polymer of conductive polymer / porous carbon material, an electrode material using the same, and an electric double layer capacitor, a lithium ion secondary battery, and a lithium ion capacitor.

State of the art

Lithium ion secondary batteries and electric double layer capacitors are known as current storage devices.

In general, the lithium-ion secondary battery has a higher energy density compared with the electric double-layer capacitor and can be operated for a long period of time.

On the other hand, compared with the lithium-ion secondary battery, the electric double-layer capacitor is capable of rapid electric charge and discharge, and the service life in repeated use is longer. Furthermore, in recent years, a lithium ion capacitor has been developed as a power storage device that combines the respective advantages of the lithium ion secondary battery with those of the electric double layer capacitor.

For example, the Applicant of the present application in Patent Document 1 for an Electric Double Layer Capacitor "discloses an electrode material for an electric double layer capacitor using a polyaniline / carbon composite formed by forming a composite of polyaniline or a derivative thereof and a carbonaceous material selected from the group consisting of activated carbon, Ketjenblack, acetylene black and furnace carbon black, wherein the polyaniline or a derivative thereof is de-doped by base treatment of conductive polyaniline or a derivative thereof dispersed in a nonpolar organic solvent. The applicant of the present application in Patent Document 2 "discloses a polyaniline / porous carbon composite material prepared by forming a composite material of porous carbon material and conductive polyaniline or a derivative thereof dispersed in a doped state in a non-polar organic solvent." ready.

Moreover, in patent document 3 for a lithium-ion capacitor, the applicant of the present application proposes an electric double layer capacitor comprising (i) a positive electrode, (ii) a negative electrode containing such an active material containing the lithium ion and (iii) an electrolytic solution comprising an aprotic organic solvent containing a lithium salt base electrolyte. In such an electric double layer capacitor, the positive electrode includes a collector and active electrode material using a conductive polyaniline-porous carbon composite formed by forming a composite of a conductive polyaniline or a derivative thereof dispersed in a doped state in a nonpolar organic solvent and porous carbon material is prepared as an active material and an assistant for electrical conduction and a binder as required. "

On the other hand, Patent Document 4 describes an electric double-layer capacitor consisting of a polarizable electrode inserted in an electrolytic solution using an electrolytic solution containing an electropolymerizable polymer precursor as an additive at a concentration of 0.005 to 0.05M; by performing initial charging, the electropolymerizable polymer precursor contained in the electrolytic solution undergoes electropolymerization; the polymer formed by the electropolymerization precipitates on electrochemically active sites on the surface of the polarizable electrode on the positive electrode side; and the electrochemically active sites are coated by the polymer. "

Documents Of The State Of The Art

Patent documents

• Patent Document 1: Japanese Patent No. 4294067
• Patent Document 2: Untested Japanese Patent Application Publication No. 2008-072079
• Patent Document 3: Untested Japanese Patent Application Publication No. 2008-300639
• Patent Document 4: Untested Japanese Patent Application Publication No. 2010-205870

Presentation of the invention

Problems to be solved by the invention

As a result of a study of polyaniline / porous carbon electrode materials and composites described in Patent Documents 1 to 3, the inventors of the present invention found that, due to factors such as the molecular weight of the polyaniline, the concentration of the polyaniline dispersion used to prepare the polyaniline Substantial differences in the presence or absence of dedoping, the dedoping process and a combination thereof or the like in the cycle characteristics occurred, particularly at the capacity retention ratio after 1,000 charge and discharge test cycles compared to the initial capacity.

Furthermore, the inventors of the present invention conducted investigations on the electric double layer capacitor described in Patent Document 4. As a result of such studies, it became clear that traces remaining after the electropolymerization in the electrolytic solution of unreacted monomers or low molecular weight composites led to side reactions with the electrolytic solution blocking the pores of the carbon material or the like, so that the cycle characteristics deteriorated.

The object of the present invention is therefore to provide an electric double layer capacitor, a lithium ion secondary battery and a lithium ion capacitor (hereinafter referred to collectively as "electric double layer capacitor or the like"), and an electrode material and a composite material used as an electrode material , which can be used to obtain the electric double layer capacitor or the like having excellent cycle characteristics.

Means of solving the problem

• (1) Verbundwerkstoff, der durch Zusammensetzen von 0,5 bis 5 Massenteilen eines leitfähigen Polymers mit Stickstoffatomen pro 100 Massenteile eines porösen Kohlenstoffmaterials gebildet wird, wobei ein Verhältnis der Peakfläche der Stickstoffatome zur Peakfläche der Kohlenstoffatome (Stickstoff/Kohlenstoff-Verhältnis) im mit Röntgen-Photoelektronenspektroskopie erhaltenen Spektrum von 0,005 bis 0,05 beträgt.
• (2) Verbundwerkstoff gemäß (1), wobei das Zahlenmittel des Molekulargewichts des leitfähigen Polymers von 2.000 bis 20.000 beträgt.
• (3) Verbundwerkstoff gemäß (1) oder (2), wobei das leitfähige Polymer mindestens eins aus der Gruppe bestehend aus Polyanilin, Polypyrrol, Polypridin, Polyquinolin, Polythiazol, Polyquinoxalin und deren Derivaten ist.
• (4) Verbundwerkstoff gemäß einem der Punkte (1) bis (3), wobei das poröse Kohlenstoffmaterial Aktivkohle und/oder Graphit ist.
• (5) Elektrodenmaterial, das den Verbundwerkstoff gemäß einem der Punkte (1) bis (4) aufweist.
• (6) Elektrischer Doppelschichtkondensator, der eine polarisierbare Elektrode, die das in (5) beschriebene Elektrodenmaterial verwendet, aufweist.
• (7) Lithium-Ionen-Sekundärbatterie, die eine negative Elektrode aus dem in (5) beschriebenen Elektrodenmaterial aufweist.
• (8) Lithium-Ionen-Kondensator, der eine positive Elektrode und/oder eine negative Elektrode aus dem in (5) beschriebenen Elektrodenmaterial aufweist.

After extensive research, the inventors of the present invention came to the present invention by discovering the possibility of obtaining an electric double-layer capacitor or the like having excellent cycle characteristics by using a composite obtained by composing a specific amount of conductive polymer with a nitrogen atom with porous carbon material the peak area ratio (nitrogen / carbon ratio) of nitrogen atoms to carbon atoms of the composite in a spectrum measured by X-ray photoelectron spectroscopy is in a certain range. In particular, the present invention provides the following items (1) to (8).

• (1) A composite formed by composing 0.5 to 5 mass parts of a conductive polymer having nitrogen atoms per 100 mass parts of a porous carbon material, wherein a ratio of the peak area of the nitrogen atoms to the peak area of the carbon atoms (nitrogen / carbon ratio) in FIG Photoelectron spectroscopy spectrum is from 0.005 to 0.05.
• (2) The composite according to (1), wherein the number average molecular weight of the conductive polymer is from 2,000 to 20,000.
• (3) The composite of (1) or (2), wherein the conductive polymer is at least one selected from the group consisting of polyaniline, polypyrrole, polypridine, polyquinoline, polythiazole, polyquinoxaline, and derivatives thereof.
• (4) The composite material according to any one of (1) to (3), wherein the porous carbon material is activated carbon and / or graphite.
• (5) An electrode material comprising the composite material according to any one of (1) to (4).
• (6) Electric double layer capacitor comprising a polarizable electrode using the electrode material described in (5).
• (7) A lithium-ion secondary battery having a negative electrode made of the electrode material described in (5).
• (8) Lithium-ion capacitor comprising a positive electrode and / or a negative electrode made of the electrode material described in (5).

Effect of the invention

As described below, the present invention can provide an electric double layer capacitor or the like having excellent cycle characteristics, an electrode material with which the electric double layer capacitor or the like can be manufactured, and a composite material used for the electrode material.

Best way to carry out the invention

[Composite Material] The composite material of the present invention is a composite formed by compounding 0.5 to 5 mass parts of a conductive polymer having nitrogen atoms per 100 mass parts of a porous carbon material, wherein the ratio (nitrogen / carbon ratio) of the peak area of the nitrogen atoms to the peak area of the carbon atoms in a spectrum obtained by X-ray photoelectron spectroscopy (hereinafter also referred to as "XPS") (hereinafter also referred to as "XPS spectrum") of 0.005 to 0.05.

The term "composite" generally refers to a material obtained by assembly and cross-linking, such as e.g. B. by combining two or more materials. However, for the purpose of the present invention, the conductive polymer having the nitrogen atom is in a state (hereinafter referred to as "compound state") in which at least a part of the conductive polymer with the nitrogen atom forms a bond with the surface of the porous carbon material and at least one Part of the conductive polymer is adsorbed with the nitrogen atom inside the pores of the porous carbon material.

In addition, the term "bonded to a surface of the porous carbon material" means that chemical bonds are formed by a reaction (acid-base reaction) between the nitrogen atom of the conductive polymer (an amino group or imino group) and acidic functional groups of the surface of the porous carbon material as exemplified by the hydroxyl group, carboxyl group or the like.

Further, the "mass (of the conductive polymer based on the porous carbon material)" refers to the amount of conductive polymer composing the composite. The mass can be determined by calculating the mass of the porous carbon material before and after the composition, for example, by calculating the added amount of conductive polymer with respect to the mass of the porous material or the like.

In addition, the mass can be determined by temperature and the amount of mass loss by thermogravimetric analysis (TGA) and further calculated by means of an elemental analysis of the composite material. Thermogravimetric analysis can be performed according to JIS K 7210: 1999 "Testing Methods of Plastics by Thermogravimetry". Specifically, before the test procedure, the porous carbon material is dried under vacuum at 200 ° C for 2 hours, then the porous carbon material remains in vacuum until its temperature reaches room temperature (i.e., 23 ± 2 ° C). The sample is then placed in a TGA device. Then, the degree of decomposition can be estimated by measuring while heating at 700 ° C at a heating rate of 20 ° C per minute while supplying nitrogen at a flow rate of 100 ml per minute. Although partial carbonization occurs in the case of a conductive polymer, the decomposition behavior and the degree of carbonization differ depending on the type of the conductive polymer. It is therefore possible to determine the amount of the composite conductive polymer based on such behavior of the conductive polymer. In addition, when the type of the conductive polymer is known, it is possible to determine the amount of the conductive polymer in the same manner as in the estimation by elemental analysis.

In addition, the term "XPS spectrum" refers to a spectrum measured by X-ray photoelectron spectroscopy.

• • Röntgenstrahlungsquelle: monochromatische Al Kα (1.486,6 eV)
• • Durchmesser des Röntgenstrahls: 100 μm
• • Röntgenstrahlungsintensität: 12,5 W, 15 kV
• • Passenergie: 69 eV (für jedes Element gleich)
• • Gemessene Elemente: C1s, N1s und O1s

The term "peak area of carbon atoms" and the term "peak area of nitrogen atoms" refer to the respective peak area calculated from the spectrum measured under the following conditions.

• X-ray source: monochromatic Al Kα (1.486.6 eV)
• • Diameter of the X-ray beam: 100 μm
• • X-ray intensity: 12.5 W, 15 kV
• • Pass Energy: 69 eV (same for each element)
• • Measured elements: C1s, N1s and O1s

In the present invention, the mass of the conductive polymer is from 0.5 to 5 mass parts per 100 mass parts of the porous carbon material, and the ratio of the peak area of the nitrogen atoms to the peak area of the carbon atoms (nitrogen to carbon ratio) in the XPS spectrum is from 0.005 to 0.05. Thus, the resulting composite material (i.e., the electrode material) can be used for obtaining an electric double-layer capacitor or the like having excellent cycle characteristics.

It is believed that this utility is due to the fact that the conductive polymer is located not only on the surface of the porous carbon material but also inside the pores of the porous carbon material where detection by XPS is difficult to react Solvents is possible to suppress the formation of deactivated radicals.

In order to achieve an interactive effect on acidic functional groups present on the surface of the porous carbon material, to avoid clogging of the pores with a diameter of 0.5 to 2 nm in the porous carbon material, which contribute to the electrostatic capacity Further, in the present invention, in order not to hinder the adsorption (compound) of the supporting salt present in the electrolyte, the mass content of the conductive polymer is preferably from 1.0 to 4.5 parts by mass, and more preferably from 1 to 3 parts by mass relative to 100 parts by mass porous carbon material.

In order to achieve an interactive effect on acidic functional groups present on the surface of the porous carbon material, to avoid clogging of the pores in the porous carbon material which contribute to the electrostatic capacity, and to the adsorption (compound) of the electrolyte in the electrolyte Further, in the present invention, the ratio (nitrogen / carbon ratio) in the XPS spectrum is preferably between 0.01 and 0.03, and more preferably between 0.01 and 0.02, in the present invention.

In the composite of the present invention, the total pore volume of all the pores having a pore diameter of 0.5 to 100.0 nm, measured according to the Horvath-Kawazoe method and the BJH method, is preferably from 0.3 to 3.0 cm ³ / g wherein the proportion of the pore volume measured by the BJH method of the pores having a diameter larger than or equal to 2.0 nm and smaller than 20.0 nm (hereinafter referred to as "mesopores") is preferably less than or equal to 15% relative to the total pore volume of the pores; the proportion of the pore volume measured by the Horvath-Kawazoe method of the pores having a diameter greater than or equal to 0.5 nm and less than 2.0 nm (hereinafter referred to as "micropores") is preferably greater than or equal to 80% relative to the total pore volume.

Due to the total pore volume, the pore volume ratio of the mesopores and the pore volume ratio of the micropores satisfying the foregoing ranges, it is possible to obtain an electric double layer capacitor having a high electrostatic capacity and further improved cycle characteristics.

It is believed that this possibility is due to the size of the mesopores permitting diffusion without steric hindrance of solvated ions, the micropores contributing significantly to the electrostatic capacity and the ion adsorption, and the ability to react with free acidic functional groups are present on the surface of the porous carbon material to suppress the occurrence of decay.

Herein, the term "Horvath-Kawazoe method" refers to the method of calculating the pore volume of small pores having diameters of 0.5 nm to 1 nm (3 Chem. Eng. Jpn., 1983, Vol. 16, p. 470) ). The term "BJH method" refers to the method of determining pore volume distribution with cylindrically shaped pore diameters (1 nm to 100.0 nm) according to the Barrett-Joyner-Halenda standard model (J.Amer.Chem.Soc., 1951 , Issue 73, pp. 373 to 377). The expression "all pores" means all pores with a diameter of 0.5 to 100.0 nm and the term "total pore volume" refers to the total value of pore volumes of all pores.

The conductive polymer and the porous carbon material used for producing the composite material of the present invention, the method for producing the composite material according to the present invention using these and the like will be described in detail below.

<Conductive polymer>

There is no particular limitation on the conductive polymer used for the production of the composite material of the present invention as long as the conductive polymer contains nitrogen atoms and becomes electrically conductive through the introduction of a dopant. The polymer may be doped with a dopant, or it may be a polymer obtained by dedoping such a polymer, such as a P or N type conductive polymer having a conductivity greater than or equal to 10 ^-9 Scm ^-1 .

Specific examples of such a P-type conductive polymer include polyaniline, polypyrrole and their derivatives. One of them may be used alone, or two or more may be used in combination. Specific examples of such n-type polymers include polypyridine, polyquinoline, polythiazole, polyquinoxaline, and derivatives of such polymers. One of them may be used alone, or two or more may be used in combination.

Of such conductive polymers, polyaniline, polypyridine and derivatives thereof are preferred because of low raw material cost and ease of synthesis.

Here, the derivative of polyaniline is exemplified by polymers obtained by polymerizing an aniline derivative (monomer) at a position other than the 4th position of the aniline having at least one substituent such as an alkyl group, alkenyl group, alkoxy group, alkylthio group, aryl group , Aryloxy group, alkylaryl group, arylalkyl group or alkoxyalkyl group.

Similarly, the derivative of polypyridine is exemplified by polymers obtained by polymerization of a pyridine derivative (monomer) which is at the 3 rd position, the 4 th position and the 6 th position with at least one substituent such as an alkyl group, alkenyl group, Alkoxy group, alkylthio group, aryl group, aryloxy group, alkylaryl group, arylalkyl group and alkoxyalkyl group.

The polyaniline, polypyrrole or derivative thereof of the present invention (hereinafter collectively referred to as "polyaniline or the like") may be summarized as a dispersion of the polyaniline or the like by chemical polymerization of the corresponding monomer (aniline, pyrrole or a derivative thereof; as "aniline or the like") in a nonpolar solvent.

Further, the dispersion of polyaniline or the like can be prepared, for example, by oxidative polymerization of aniline or the like in a non-polar solvent containing added dopant. From the viewpoint of fixing the content of the conductive polymer in the obtained composite of the present invention in the aforementioned range and from the standpoint of adjusting the ratio (nitrogen / carbon ratio) in the XPS spectrum in the aforementioned range, it is important to control the concentration of the doped polyaniline or the like in the dispersion and to adjust the number average molecular weight of the polyaniline or the like in the composition described below with the porous carbon material.

The concentration of the polyaniline or the like in the doped state in the above-mentioned dispersion is preferably 0.1 to 3% by mass, more preferably 0.1 to 1.0% by mass, and most preferably 0.1 to 0.5% by mass.

The number average molecular weight of the polyaniline or the like used in the porous carbon material composition described below is preferably 2,000 to 20,000, more preferably 3,000 to 15,000, and particularly preferably 5,000 to 10,000 so as not to elute into the material during charging and discharging Electrolyte solution comes, and so as not to clog the pores.

Here, the number-average molecular weight is measured by dedoping by a method such as a base treatment, whereby the polyaniline or the like is subsequently recovered as a precipitate, and then the number-average molecular weight is measured by gel permeation chromatography (GPC). The number average molecular weight refers to the value in terms of polystyrene as a known molecular weight. In the present invention, the number average molecular weight of the doped polyaniline or the like in the dispersion is understood as being measured by this method.

An adjustment of the number-average molecular weight of the polyaniline or the like in a doped state in the dispersion may be carried out according to the amount of a molecular weight-adjusting agent (i.e., end-capping agent). In particular, the amount of the molecular weight adjusting agent (i.e., end capping agent) added in the polymerization of the polyaniline or the like is preferably 0.1 to 1 equivalent with respect to the aniline or the like.

On the other hand, the polypyridine, polyquinoline, polythiazole, polyquinoxaline or derivative thereof (hereinafter referred to collectively as the "polypyridine or the like") can be prepared as a dispersion of polypyridine or the like by dehalogenation polycondensation of the corresponding monomer in an aprotic or nonpolar solvent.

Exemplary methods for preparing the dispersion of the polypyridine or the like include: a method for producing by dissolving and dispersing the polypyridine or the like in an organic acid such as formic acid or the like; a method of preparation by mixing a solution of polypyridine or the like dissolved in an organic acid such as formic acid or the like and a solution of a dissolved polymer having an acidic group (e.g., polystyrene sulfonate or the like); a process for producing by dissolving and dispersing the polypyridine or the like in an organic acid (e.g., formic acid or the like) containing a dissolved polymer having acidic groups (e.g., polystyrene sulfonate or the like); or similar.

The concentration values of the polypyridine or the like in the dispersion, the number average molecular weight of the polypyridine or the like during the composition with the porous carbon material described below, and the amount of a molecular weight adjusting agent used during the polymerization are the same as those used for the polymerization of polyaniline or The same can be used, approximately identical.

Any of the dopants or oxidizing agents, molecular weight adjusting agents, phase transfer catalysts or the like for chemical polymerization (oxidative polymerization) described in Patent Document 1 can be used as such components for the present invention.

<Porous carbon material>

The specific surface area of the porous carbon material used in the production of the composite material of the present invention is not particularly limited. However, from the viewpoint of adjusting the content of conductive polymer in the composite of the present invention in the above-mentioned range and from the standpoint of adjusting the ratio (nitrogen / carbon ratio) in the XPS spectrum in the above-mentioned range, the carbon material preferably has a specific surface area from 1,000 to 3,000 m ² / g.

Specific examples of the porous carbon material include activated carbon, graphite, boron-containing porous carbon material, nitrogen-containing porous carbon material, or the like. One of them may be used alone, or two or more may be used in combination. Of these, activated carbon and / or graphite are preferred because they are readily available.

With respect to the activated carbon, there are no particular limitations and conventional activated carbon particles used in carbon electrodes and the like can be used. Specific examples include activated charcoal particles formed by activating coconut shells, wood flour, petroleum pitch, phenolic resins, and the like with steam, various chemicals, alkali, and the like. One of them may be used alone, or two or more may be used in combination.

Further, the graphite is not limited in any particulars and any known graphite used as the negative electrode active material of a lithium ion secondary battery or the like can be used. Specific examples of such graphite include natural graphite, artificial graphite, graphitized meso-carbon microspheres, graphitized mesophase pitch carbon fibers, or the like. One of them may be used alone, or two or more may be used in combination.

<Method for producing the composite material>

The method described below may be cited as an exemplary method for producing the composite of the present invention using the conductive polymer and the porous carbon material.

In particular, after the conductive polymer and the porous carbon material have been mixed, the dopant may be removed by dedoping to form the composite of the conductive polymer and the porous carbon material.

The method for mixing the conductive polymer and the porous carbon material is not particularly limited. Specific examples of methods of mixing the conductive polymer and the porous carbon material include: for example, a method of mixing the entire amount of the porous carbon material with a dispersion of the conductive polymer; a method of producing a pre-composite by mixing a dispersion of the conductive polymer with a part of the porous carbon material, and then mixing the pre-composite with the remaining porous carbon material or the like.

Preferred methods of dedoping include: a method of dedoping the doped conductive polymer and conducting a treatment with a base that can neutralize the dopant; a method of heat-treating the dopant at a temperature that does not destroy the conductive polymer; or similar.

Of such preferred methods of dedoping, dedoping by heat treatment due to the non-use of chemical reagents and organic solvents, completion of treatment within a short time interval due to lack of base reaction requirement and absence of salt residue and lack of need for washing step of washing Salt after the reaction is preferred. The dedoping by heat treatment is highly suitable for industrial use due to such reasons.

Specific examples of the above-mentioned base treatment include: a method using a basic substance for treating the composite or a dispersion (mixed dispersion) obtained by mixing the conductive polymer and the porous carbon material; a method for mixing the mixed dispersion or the composite with water and / or organic solvent in which the basic substance is dissolved; a method for effecting contact between the mixed dispersion or the composite with a gas of the basic substance or the like. The basic substance includes, for example, ammonia water, sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide, calcium hydroxide and other metal hydroxides; Methylamine, ethylamine, triethylamine and other amines; Tetramethylammonium hydroxide, tetraethylammonium hydroxide and other alkylammonium hydroxides; Hydrazine, phenylhydrazine and other hydrazine compounds; Diethylhydroxylamine, dibenzylhydroxylamine and other hydroxylamine compounds and the like. Furthermore, the organic solvent may be any organic solvent that dissolves the basic substance. Specific examples of the organic solvent include aromatic hydrocarbons such as toluene, xylene or the like; aliphatic hydrocarbons such as hexane, heptane, cyclohexane or the like; halogenated hydrocarbons such as chloroform, dichloromethane or the like; Esters such as ethyl acetate, butyl acetate or the like; Alcohols such as methanol, ethanol or the like; Sulfoxides such as dimethylsulfoxide or the like; Amides such as dimethylformamide or the like; Carbonic acid esters such as propylene carbonate, dimethyl carbonate, diethyl carbonate or the like; Lactones such as γ-butyrolactone, γ-valerolactone or the like; Nitriles such as acetonitrile, propionitrile or the like; N-methyl-2-pyrrolidone or the like.

The heat treatment is performed at a temperature appropriately selected for the degradation and removal of the dopant alone, without particularly affecting the properties of the conductive polymer. The heat treatment, for example, preferably at at least 20 ° C below the degradation temperature of the conductive polymer as measured by thermogravimetric analysis. In particular, the heat treatment is more preferably carried out at a temperature greater than or equal to 250 ° C and less than 400 ° C.

The composite of the present invention is preferably formed by employing treatment with a base to dedoping the dopant in the conductive polymer, although it is also permissible to use a conductive polymer which has not been completely dedoped.

The amount of the dopant contained in the conductive polymer after the treatment with a base, as indicated by the molar ratio per monomer unit of the conductive polymer, is preferably 0 to 0.3, and more preferably 0 to 0.1.

A conventional mixing apparatus can be used for preparing the mixture of the conductive polymer and the porous carbon material, such as mixing / dispersing equipment such as a sand mill, a bead mill, a ball mill, a planetary ball mill, a three-roll mill, a colloid mill, an ultrasonic homogenizer, a Henschel mixer , a jet mill, a planetary mixer or the like exemplified.

[Electrode material]

The electrode material of the present invention is an electrode material employing the composite of the present invention as the active material. In particular, the electrode material of the present invention may be used as the material of the polarizable electrode of the below-described electric double layer capacitor of the present invention, as a negative electrode material of a lithium ion secondary battery and as the materials of the negative and / or positive electrode of a lithium ion battery. Condenser can be used.

[Electric double layer capacitor]

The electric double layer capacitor of the present invention is an electric double layer capacitor having a polarizable electrode formed by using the electrode material of the present invention.

[Lithium ion secondary battery]

The lithium ion secondary battery of the present invention is a lithium ion secondary battery having a negative electrode formed using the electrode material of the present invention.

[Lithium-ion capacitor]

The lithium ion capacitor of the present invention is a lithium ion capacitor having a positive and / or a negative electrode formed using the electrode material of the present invention.

The polarizable electrode, the positive electrode, and the negative electrode in the electric double layer capacitor, the lithium ion secondary battery, and the lithium ion capacitor of the present invention (hereinafter referred to as the "electric double layer capacitor or the like of the present invention") For example, composed of the composite of the present invention and a collector (eg, platinum, copper, nickel, aluminum, or the like).

Although a binder or conduction aid is not necessarily required because the polarizable electrode includes the conductive polymer, a binder or conductivity assistant may be used as needed. When a binder or conductivity assistant is used, the electrode material of the present invention may use the binder or conductivity assistant together with the conductive polymer and the porous carbon material.

Specific examples of the binder include polyvinylidene fluoride, polytetrafluoroethylene, fluoro-olefin copolymers, carboxymethyl cellulose, polyvinyl alcohol, polyacrylic acid, polyvinyl pyrrolidone, polymethyl methacrylate or the like.

Specific examples of the conduction aid include carbon black (especially acetylene black and Ketjenblack), natural graphite, thermally expandable graphite, carbon fibers, nanocarbon material, ruthenium oxide, metal fiber (eg, aluminum, nickel or the like) or the like.

Besides the electrode material (composite material) of the present invention used as the polarizable electrode, a conventional structure may be applied to the electric double layer capacitor or the like of the present invention, and the electric double layer capacitor or the like of the present invention may be manufactured by conventionally known manufacturing methods ,

Examples

The present invention will now be described in more detail by the following examples, but is by no means limited to these embodiments.

<Preparation of Polyaniline-Toluene Dispersion 1>

1.2 g of aniline, 2.6 g of dodecylbenzenesulfonic acid and 0.26 g of 2,4,6-trimethylaniline (0.15 equivalent in terms of aniline) as a molecular weight adjusting agent (end capping agent) were dissolved in 200 g of toluene ,

Thereafter, to this mixture was added 100 g of distilled water in which 2.2 ml of 6N hydrochloric acid was dissolved.

To the mixed solution, 0.36 g of tetrabutylammonium bromide was added, the mixture was cooled to 5 ° C or lower, and then 80 g of distilled water in which 3.52 g of ammonium persulfate was dissolved was added.

The mixture was oxidatively polymerized in a state of 5 ° C or lower for 6 hours, then 100 g of toluene and then a methanol-water mixed solvent (water / methanol = 2/3 (mass ratio)) were added thereto, and the resultant mixture was touched.

After completion of the stirring, the reaction solution was separated into the toluene layer and the aqueous layer, and only the aqueous layer was stripped off to obtain a polyaniline-toluene dispersion 1.

A part of the polyaniline-toluene dispersion 1 was taken out and the toluene was distilled off in vacuo to find that the dispersion contained 1.2 mass% of a solid component (polyaniline content: 0.4 mass%, number average molecular weight = 7,800).

Further, this dispersion was filtered through a filter having a pore size of 1.0 μm, after which there was no clogging. The particle size of the polyaniline particles in the dispersion was analyzed by an ultrasonic particle size distribution measuring apparatus (APS-100, manufactured by Matec Applied Sciences). As a result, it was learned that the particle size distribution was monodispersion (the peak value was 0.19 μm, the half width was 0.10 μm).

Furthermore, the dispersion did not lump or precipitate even at lapse of 1 year at room temperature and was thus stable. According to elemental analysis, the molar ratio of the dodecylbenzenesulfonic acid per aniline monomer unit was 0.45. The yield of the obtained polyaniline was 95%.

<Preparation of Polyaniline-Toluene Dispersion 2>

Polyaniline-toluene dispersion 2 was obtained by polymerization by the same method as that for the polyaniline-toluene dispersion 1 except for using 0.52 g of 2,4,6-trimethylaniline (0.30 equivalent with respect to the aniline ).

A part of the polyaniline-toluene dispersion 2 was taken out and the toluene was distilled off in vacuo to find that the dispersion contained 1.4 mass% of a solid component (polyaniline content: 0.4 mass%, number average molecular weight = 5,600). Further, this dispersion was filtered through a filter having a pore size of 1.0 μm, after which there was no clogging. The particle size of the polyaniline particles in the dispersion was measured with an ultrasonic device for measuring the Particle Size Distribution (APS-100, manufactured by Matec Applied Sciences). As a result, it was learned that the particle size distribution was monodispersion (the peak value was 0.14 μm, the half width was 0.08 μm).

Furthermore, the dispersion did not lump or precipitate even at lapse of 1 year at room temperature and was thus stable. According to elemental analysis, the molar ratio of the dodecylbenzenesulfonic acid per aniline monomer unit was 0.45. The yield of the obtained polyaniline was 93%.

<Preparation of Polyaniline-Toluene Dispersion 3>

Polyaniline-toluene dispersion 3 was obtained by polymerization by the same method as that for the polyaniline-toluene dispersion 1 except for using 0.52 g of 2,4,6-trimethylaniline (0.20 equivalent in terms of aniline ).

A part of the polyaniline-toluene dispersion 3 was taken out and the toluene was distilled off in vacuo to find that the dispersion contained 1.4 mass% of a solid component (polyaniline content: 0.4 mass%, number average molecular weight = 6,500). Further, this dispersion was filtered through a filter having a pore size of 1.0 μm, after which there was no clogging. The particle size of the polyaniline particles in the dispersion was analyzed by an ultrasonic particle size distribution measuring apparatus (APS-100, manufactured by Matec Applied Sciences). As a result, it was learned that the particle size distribution was monodispersion (the peak value was 0.10 μm, the half-width was 0.07 μm).

Furthermore, the dispersion did not lump or precipitate even at lapse of 1 year at room temperature and was thus stable. According to elemental analysis, the molar ratio of the dodecylbenzenesulfonic acid per aniline monomer unit was 0.45. The yield of the obtained polyaniline was 93%.

<Preparation of aqueous polypyridine dispersion>

In 50 g of dry dimethylformamide, 5 g of 2,5-dibromopyridine, 0.5 g of 2-bromopyridine as a molecular weight adjusting agent (0.15 equivalents relative to the pyridine monomer) and 9 g of bis (1.5 cyclooctadiene) nickel as a polycondensation agent. Thereafter, the polymerization reaction was carried out at 60 ° C for 16 hours under nitrogen. After completion of the reaction, the polypyridine was purified by the procedure described below.

First, the reaction solution was poured into 200 ml of 0.5 mol / L aqueous hydrochloric acid solution. After 2 hours of stirring at room temperature, the precipitate was filtered out and recovered.

Thereafter, the recovered precipitate was again stirred for 8 hours at room temperature in 200 ml of 0.5 mol / L aqueous hydrochloric acid solution, and the precipitate was filtered out and recovered.

Thereafter, the recovered precipitate was stirred for 3 hours at room temperature in 200 ml of 0.1 mol / l aqueous ammonium solution to isolate and purify the polypyridine.

The resulting polypyridine powder was dried under vacuum. 1.72 g were recovered (yield of 92%).

A polypyridine-formic acid solution was previously prepared by dissolving 0.8 g of polypyridine powder in 9.2 g of 88% formic acid. This polypyridine-formic acid solution and 15 g of 18% aqueous polystyrene sulfonate solution were mixed and stirred. Thereafter, 175 g of distilled water was added to prepare an aqueous polypyridine dispersion (containing 0.4% by mass of polypyridine, number average molecular weight of polypyridine = 10,000).

The particle size of the polypyridine particles in the dispersion was analyzed by an ultrasonic particle size distribution measuring apparatus (APS-100, manufactured by Matec Applied Sciences). As a result, it was learned that the particle size distribution was monodispersion (i.e., the peak value was 0.25 μm, the half-width was 0.12 μm).

<Preparation of Polypyrrole Dispersion>

In 150 g of toluene was dissolved 3 g of pyrrole, 12.0 g of dodecylbenzenesulfonic acid and 0.15 g of 2-methylpyrrole as a molecular weight adjusting agent (end capping agent). Thereafter, 75 g of distilled water was added, in which 5.36 ml of 6N hydrochloric acid had been dissolved. To this mixed solvent was added 0.9 g of tetrabutylammonium bromide. After performing oxidative polymerization for 6 hours at temperatures less than or equal to 0 ° C, 100 g of toluene and then methanol / water mixed solvent (methanol: water = 2: 3 (mass ratio)) were successively added, and the mixture was stirred. After completion of the stirring, the reaction solution was separated into the toluene layer and the aqueous layer, and only the aqueous layer was peeled off to obtain a polypyrrole-toluene dispersion.

A part of the polypyrrole-toluene dispersion was taken out and the toluene was distilled off in vacuo to find that the dispersion contained 4.1 mass% of a solid component (pyrrole content = 1.2 mass%, number average molecular weight of polypyrrole = 10,000). Further, this dispersion was filtered through a filter having a pore size of 1.0 μm, after which there was no clogging.

Furthermore, the dispersion did not lump or precipitate even at lapse of 1 year at room temperature and was thus stable. According to the elemental analysis, the molar ratio of the dodecylbenzenesulfonic acid per anion monomer unit was 0.95. The yield of the obtained polypyrrole was 94%.

<Polyaniline xylene dispersion>

A commercial polyaniline-xylene dispersion was used (NX-B001, polyaniline content = 1.0 mass%, number average molecular weight of polyaniline = 1,500, manufactured by Ormecon).

Production of a composite material 1

In 250 g of the polyaniline-toluene dispersion 1 (polyaniline content = 1 g), 89 g of activated carbon (NK260, specific surface area = 2000 m ² / g, content of acidic functional groups = 0.1 mmol, manufactured by Kuraray Chemical Co., Ltd.) was added to obtain a mixed dispersion.

To the mixed dispersion was added 50 ml of a 2 mol / liter solution of triethylamine in methanol, then the mixture was stirred for 5 hours and mixed.

After completion of the stirring, the precipitate was collected by filtration and washed with methanol. The filtrate and wash solution were colorless and transparent at this time.

The washed and purified precipitate was dried under vacuum to produce a polyaniline / activated carbon composite (hereinafter referred to as "Composite 1").

In the composite material 1 thus obtained, the content of conductive polymer per 100 mass parts of the porous carbon material was determined.

The ratio (nitrogen / carbon ratio) of the peak area of the nitrogen atoms and the peak area of the carbon atoms in the XPS spectrum measured by an X-ray photoelectron spectrometer (Model: Quanter SMX, manufactured by ULVAC-PHI, Inc.) became the obtained composite material 1 calculated. These results are shown in Table 1 below. In Table 1, the numerical values for the content in the respective dispersion indicating the content of the conductive polymer in the dispersion are given in parentheses.

A device for rapid measurement of specific surface area / pore distribution (model ASAP 2020, manufactured by Shimadzu Micrometitics) was used to measure the pore volume of the resulting composite 1.

In particular, after drying the sample 6 for 6 hours at 150 ° C, nitrogen gas was used as the adsorption gas and liquid nitrogen as the refrigerant. The total pore volume was measured by the Horvath-Kawazoe method and the BJH method, the pore volume of pores having a diameter larger than or equal to 2.0 nm and smaller than 20.0 nm was measured, and the pore volume of pores having a diameter larger than or equal to zero , 5 nm and smaller than 2.0 nm was measured. Based on the measured values the pore volume ratios of each pore volume were calculated. These results are shown in Table 1 below.

Production of a composite material 2

In 1,000 g of the polyaniline-toluene dispersion 1 (polyaniline content = 4 g), 86 g of activated carbon (NK260, specific surface area = 2000 m ² / g, content of acidic functional groups = 0.1 mmol, manufactured by Kuraray Chemical Co., Ltd.) was added to obtain a mixed dispersion.

To the mixed dispersion was added 50 ml of a 2 mol / liter solution of triethylamine in methanol, then the mixture was stirred for 5 hours and mixed.

After completion of the stirring, the precipitate was collected by filtration and washed with methanol. The filtrate and wash solution were colorless and transparent at this time.

The washed and purified precipitate was dried under vacuum to produce a polyaniline / activated carbon composite (hereinafter referred to as "Composite 2").

In the composite material 2 thus obtained, the ratio (nitrogen / carbon ratio) of the peak area of the nitrogen atoms and the peak area of the carbon atoms in the XPS spectrum and the content of the conductive polymer based on 100 mass parts of the porous carbon material were calculated as in the composite material 1 and each of the pore volume values measured by the same method as Composite 1 was used to calculate the pore volume ratios of each pore volume. These results are shown in Table 1 below.

Production of composite material 3

A composite of polyaniline and activated carbon (hereinafter referred to as "Composite 3") was prepared by the same method as Composite 1 except that 250 g of polyaniline-toluene dispersion 2 (polyaniline content = 1 g) was used instead of polyaniline-toluene dispersion 1 were.

In the composite material 3 thus obtained, the ratio (nitrogen / carbon ratio) of the peak area of the nitrogen atoms and the peak area of the carbon atoms in the XPS spectrum and the content of the conductive polymer based on 100 parts by mass of the porous carbon material were calculated, and the same as in the composite material 1 each of the pore volume values measured by the same method as Composite 1 was used to calculate the pore volume ratios of each pore volume. These results are shown in Table 1 below.

Production of composite material 4

A composite of polyaniline and activated carbon (hereinafter referred to as "Composite 4") was prepared by the same method as Composite 1 except that 250 g of polyaniline-toluene dispersion 3 (polyaniline content = 1 g) was used instead of polyaniline-toluene dispersion 1 were.

In the composite 4 thus obtained, the ratio (nitrogen / carbon ratio) of the peak area of the nitrogen atoms and the peak area of the carbon atoms in the XPS spectrum and the content of the conductive polymer with respect to 100 mass parts of the porous carbon material were calculated as in Compound 1, and each of the pore volume values measured by the same method as Composite 1 was used to calculate the pore volume ratios of each pore volume. These results are shown in Table 1 below.

Production of composite material 5

A composite of polypyridine and activated carbon (hereinafter referred to as "composite material 5") was prepared by the same method as Composite 1 except that 250 g of the aqueous polypyridine dispersion (polypyridine content = 1 g) was used instead of the polyaniline-toluene dispersion 1.

In the composite material 5 thus obtained, the ratio (nitrogen / carbon ratio) of the peak area of the nitrogen atoms and the peak area of the carbon atoms in the XPS spectrum and the content of the conductive polymer with respect to 100 mass parts of the XPS spectrum were the same as in the composite material 1 of porous carbon material, and each of the pore volume values measured by the same method as in Composite 1 was used to calculate the pore volume ratios of each pore volume. These results are shown in Table 1 below.

Production of composite material 6

93 g of graphite (solid mesophase graphite, manufactured by JFE Chemical Corp.) was added in 500 g of the polyaniline-toluene dispersion 1 (polyaniline content = 2 g) to obtain a mixed dispersion.

To the mixed dispersion was added 50 ml of a 2 mol / liter solution of triethylamine in methanol, then the mixture was stirred for 5 hours and mixed.

After completion of the stirring, the precipitate was collected by filtration and washed with methanol. The filtrate and wash solution were colorless and transparent at this time.

The washed and purified precipitate was dried under vacuum to produce a polyaniline / graphite composite (hereinafter referred to as "Composite 6").

In the composite material 6 thus obtained, the ratio (nitrogen / carbon ratio) of the peak area of the nitrogen atoms and the peak area of the carbon atoms in the XPS spectrum and the content of the conductive polymer based on 100 mass parts of the porous carbon material were calculated as in the composite material 1. These results are shown in Table 1 below. In addition, in the composite 6 using the graphite as the porous carbon material, the pore volume could not be measured, and therefore the entry is marked as "-" in Table 1 below.

Production of composite material 7

A composite of polypyrrole and activated carbon (hereinafter referred to as "Composite 7") was prepared in the same manner as Composite 6, except that 167 g of the polypyrrole-toluene dispersion (polypyrrole content = 2 g) was used instead of the polyaniline-toluene dispersion 1 ,

In the composite material 7 thus obtained, the ratio (nitrogen / carbon ratio) of the peak area of the nitrogen atoms and the peak area of the carbon atoms in the XPS spectrum and the content of the conductive polymer based on 100 mass parts of the porous carbon material were calculated as in the composite 1. These results are shown in Table 1 below. In addition, in the composite 7 using the graphite as the porous carbon material, the pore volume could not be measured, and therefore the entry is marked as "-" in Table 1 below.

Production of composite material 8

To 3750 g of polyaniline-toluene dispersion 1 (polyaniline content = 15 g) was added 75 g of activated carbon (NK260, specific surface area = 2,000 m ² / g, content of acidic functional groups = 0.1 mmol, manufactured by Kuraray Chemical Co., Ltd.) to obtain a mixed dispersion.

To the mixed dispersion was added 50 ml of a 2 mol / liter solution of triethylamine in methanol, then the mixture was stirred for 5 hours and mixed.

After completion of the stirring, the precipitate was collected by filtration and washed with methanol. The filtrate and wash solution were colorless and transparent at this time.

The washed and purified precipitate was dried under vacuum to produce a polyaniline / graphite composite (hereinafter referred to as "Composite 8").

In the composite material 8 thus obtained, the ratio (nitrogen / carbon ratio) of the peak area of the nitrogen atoms and the peak area of the carbon atoms in the XPS spectrum and the content of the conductive polymer based on 100 mass parts of the porous carbon material were calculated, and the same as in the composite material 1, and each of the pore volume values measured by the same method as Composite 1 was used to calculate the pore volume ratios of each pore volume. These results are shown in Table 1 below.

Production of composite material 9

A polyaniline-NMP solution (polyaniline content = 0.4 mass%) was prepared by dissolving 0.4 g of a commercial polyaniline powder (manufactured by Sigma-Aldrich Co., LLC, number average molecular weight = 3900) in 99.6 g of N-methyl 2-pyrrolidone (NMP).

To 250 g of the polyaniline-NMP dispersion (polyaniline content = 1 g) was added 89 g of activated carbon (NK260, specific surface area = 2,000 m ² / g, content of acidic functional groups = 0.1 mmol, manufactured by Kuraray Chemical Co., Ltd .) to obtain a mixed dispersion.

A composite of polyaniline and activated carbon (hereinafter referred to as "composite 9") was prepared by vacuum distillation by heating and removing the NMP from the mixed dispersion.

In the composite material 9 thus obtained, the ratio (nitrogen / carbon ratio) of the peak area of the nitrogen atoms and the peak area of the carbon atoms in the XPS spectrum and the content of the conductive polymer with respect to 100 mass parts of the porous carbon material were calculated, as in the composite material 1, and each of the pore volume values measured by the same method as Composite 1 was used to calculate the pore volume ratios of each pore volume. These results are shown in Table 1 below.

Production of composite material 10

To 1,000 g of the polyaniline-NMP dispersion (polyaniline content = 4 g) was added 86 g of activated carbon (NK260, specific surface area = 2,000 m ² / g, content of acidic functional groups = 0.1 mmol, manufactured by Kuraray Chemical Co., Ltd .) to obtain a mixed dispersion.

A composite of polyaniline and activated carbon (hereinafter referred to as "composite material 10") was prepared by vacuum distillation by heating and removing the NMP from the mixed dispersion.

In the composite material 10 thus obtained, the ratio (nitrogen / carbon ratio) of the peak area of the nitrogen atoms and the peak area of the carbon atoms in the XPS spectrum and the content of the conductive polymer with respect to 100 mass parts of the porous carbon material were calculated, as in the composite 1 each of the pore volume values measured by the same method as Composite 1 was used to calculate the pore volume ratios of each pore volume. These results are shown in Table 1 below.

Production of composite material 11

To 75 g of the polyaniline-NMP dispersion (polyaniline content = 0.3 g) was added 89.7 g of activated carbon (NK260, specific surface area = 2,000 m ² / g, content of acidic functional groups = 0.1 mmol, manufactured by Kuraray Chemical Co., Ltd.) to obtain a mixed dispersion.

A composite of polyaniline and activated carbon (hereinafter referred to as "Composite 11") was prepared by vacuum distillation by heating and removing the NMP from the mixed dispersion.

In the composite material 11 thus obtained, the ratio (nitrogen / carbon ratio) of the peak area of the nitrogen atoms and the peak area of the carbon atoms in the XPS spectrum and the content of the conductive polymer with respect to 100 mass parts of the porous carbon material were calculated as in Compound 1, and each of the pore volume values measured by the same method as Composite 1 was used to calculate the pore volume ratios of each pore volume. These results are shown in Table 1 below.

Production of composite material 12

89 g of activated carbon (NK260, specific surface area = 2,000 m ² / g, content of acidic functional groups = 0.1 mmol, manufactured by Kuraray Chemical Co.) was added to 100 g of a polyaniline-xylene dispersion (NX-B001, polyaniline content 1.0 mass%, number average molecular weight of polyaniline = 1,500, manufactured by Ormecon) to obtain a mixed dispersion.

To the mixed dispersion was added 50 ml of a 2 mol / liter solution of triethylamine in methanol, then the mixture was stirred for 5 hours and mixed.

After completion of the stirring, the precipitate was collected by filtration and washed with methanol. The filtrate and wash solution were colorless and transparent at this time.

The washed and cleaned precipitate was dried under vacuum to produce a polyaniline / active carbon composite (hereinafter referred to as "Composite 12").

In the composite material 12 thus obtained, the ratio (nitrogen / carbon ratio) of the peak area of the nitrogen atoms and the peak area of the carbon atoms in the XPS spectrum and the content of the conductive polymer based on 100 mass parts of the porous carbon material were calculated, and the composite material 1 each of the pore volume values measured by the same method as Composite 1 was used to calculate the pore volume ratios of each pore volume. These results are shown in Table 1 below.

Production of composite material 13

93 g of graphite (solid mesophase graphite, manufactured by JFE Chemical Corp.) was added to 500 g of the polyaniline-NMP solution (polyaniline content = 2 g) to obtain a mixed dispersion.

The NMP was removed from the mixed dispersion by heating and vacuum distillation to prepare a composite of polyaniline and graphite (hereinafter referred to as "composite material 13").

Tabelle 1-II Tabelle 1-1

Tabelle 2-I Tabelle 1-2

Tabelle 2-II Tabelle 1-2

In the composite material 13 thus obtained, the ratio (nitrogen / carbon ratio) of the peak area of the nitrogen atoms and the peak area of the carbon atoms in the XPS spectrum and the content of the conductive polymer based on 100 mass parts of the porous carbon material were calculated as in the composite material 1. These results are shown in Table 1 below. Moreover, in the composite material 13 using the graphite as the porous carbon material, the pore volume could not be measured, and therefore the entry is marked as "-" in Table 1 below. Table 1-I Table 1-1

Table 1-II Table 1-1

Table 2-I Table 1-2

Table 2-II Table 1-2

<Preparation of an electrode for evaluation: Working Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-8>

Composites 1 to 13, activated carbon 1 or graphite, a conduction aid (acetylene black) or a binder (SBR) and a binder (carboxymethyl cellulose) were mixed and dispersed in the composition ratios shown in Table 2 below.

Thereafter, water was added little by little, and the mixture was further mixed to prepare a paste-like substance.

Tabelle 4 Tabelle 2-2

This paste was applied to an aluminum collector electrode foil (30 μm thick) to give a thickness of 60 μm. Thereafter, the assembly was dried at 150 ° C for 24 hours. After compression treatment of the plate-like electrodes at 20 MPa, disc-like patterns were cut out (diameter of 1 cm) to prepare evaluation electrodes A to O. Table 3 Table 2-1

Table 4 Table 2-2

<Electric double layer capacitor: Working Examples 2-1 to 2-5, Comparative Examples 2-1 to 2-7>

In the embodiments 2-1 to 2-4, the evaluation electrodes A, B, C, and D, respectively, made of the composites 1 to 4 were used as positive electrodes. The evaluation electrode H made of activated carbon was used as the negative electrode.

In Embodiment 2-5, the evaluation electrode H made of activated carbon was used as the positive electrode, and the evaluation electrode E made of the composite material 5 was used as the negative electrode.

In Comparative Example 2-1, the evaluation electrodes I made of activated carbon 1 were used as both the positive and negative electrodes.

On the other hand, in Comparative Examples 2-2 to 2-6, the evaluation electrodes I to M (made of the composite materials 8 to 12) were used as the positive electrodes. The evaluation electrode H made of the activated carbon was used as the negative electrode.

Further, the evaluation electrodes H made of activated carbon in Comparative Example 2-7 were used as both electrodes, and according to Patent Document 4, aniline was dissolved in a propylene carbonate solution to obtain a concentration of 0.03M.

An electric double layer capacitor was constructed by using positive and negative electrodes separated by a separator made of glass fiber (manufactured by Nippon Sheet Glass Co., Ltd.) and using a 1 mol / L solution of tetraethylammonium tetrafluoroborate prepared in propylene carbonate as the electrolytic solution.

<Lithium Ion Secondary Battery: Working Examples 3-1 and 3-2 and Comparative Examples 3-1 and 3-2>

The negative electrode used in Embodiment 3-1 was the evaluation electrode F made of composite 6, and the positive electrode was the active material (positive electrode active material) described below. The negative electrode used in Embodiment 3-2 was the evaluation electrode G made of composite material 7, and the positive electrode was the active substance (positive electrode active substance) described below.

The negative electrode used in Comparative Example 3-1 was the evaluation electrode N made of graphite. The negative electrode used in Comparative Example 3-2 was the evaluation electrode O made of composite material 13. The active material (positive electrode active material) listed below was incorporated into the both Comparative Examples 3-1 and 3-2 are used as a positive electrode.

(Active material of positive electrode)

10 parts by mass of binder (SBR), 10 parts by mass of conductibility aid (acetylene black) and 10 parts by mass of a binder (Teflon (Registered Trade Mark)) were added with ethyl acetate to 100 parts by mass of lithium cobaltate. The mixture was kneaded and the resulting kneading material was used as the positive electrode active substance.

The positive and negative electrodes faced each other and were separated by a propylene separator (U-Pore, manufactured by Ube Industries, Ltd.). With 1 mol / l of a lithium hexafluorophosphate-diethyl carbonate / ethylene carbonate solution as the electrolytic solution, a lithium secondary battery was prepared.

<Lithium Ion Capacitor: Working Examples 4-1 to 4-3, Comparative Example 4-1>

In Embodiment 4-1, the evaluation electrode N made of graphite was used as the negative electrode, and the evaluation electrode A made of the composite material 1 was used as the positive electrode.

In Embodiment 4-2, the evaluation electrode F made of composite 6 was used as a negative electrode, and the evaluation electrode H made of activated carbon was used as a positive electrode.

In Embodiment 4-3, the evaluation electrode F made of composite 6 was used as the negative electrode, and the evaluation electrode A made of the composite material 1 was used as the positive electrode.

In Comparative Example 4-1, the evaluation electrode N made of graphite was used as the negative electrode, and the evaluation electrode H made of activated carbon was used as the positive electrode.

Specifically, first, the positive and negative electrodes were stacked with the separator therebetween, and then the assembly was dried under vacuum at 150 ° C for 12 hours.

Then, a single slice of the separator was placed on the outside of each electrode and the 4 sides were hermetically sealed to produce the lithium-ion capacitor element.

Subsequently, metallic lithium was compressed to 70 μm thick copper grid with respect to the mass amount of the negative electrode active material to provide doping with an ion concentration of 350 mAh / g, and 1 plate of this material was placed on the outermost part of the lithium ion capacitor element Counterpart to the negative electrode arranged.

After inserting the lithium-ion capacitor element into which metallic lithium was introduced in an outer laminate cover layer, the device was impregnated under vacuum conditions using an electrolytic solution containing 1.2M LiPF ₆ dissolved in propylene carbonate.

Subsequently, the outer laminate cover layer was heat-sealed under vacuum conditions to join the lithium-ion capacitor cell.

<Electrostatic capacity and cycle characteristics>

(Electric double layer capacitor)

The prepared electric double layer capacitors were subjected to a charging / discharging test using a charging / discharging tester (HJ1001SM8A manufactured by Hokuto Denko Corp.). The charging was carried out at 60 ° C by a constant current of 2 mA. After the voltage reached 3.0 V, the charging was performed by charging at a constant voltage for 1 hour. The discharge was carried out at 60 ° C by a constant current of 2 mA and a final voltage of 0V.

The charge / discharge test was repeated 1,000 times for each capacitor. The electrostatic capacity per positive electrode material in the first discharge was set as an initial electric capacity (i.e., electrostatic capacity per unit weight of the positive electrode), and the ratio of maintaining the electrostatic capacity relative to the initial electrostatic capacity was determined. These results are shown in Table 3 below.

(Lithium ion secondary battery)

The charge / discharge test of the produced lithium ion secondary batteries was carried out in the manner described below.

First, the battery was charged with a constant current of 2 mA until the battery voltage reached 4.2V. Thereafter, the constant-current charging was switched to a constant-voltage charging of 4.2V, and the charging was completed when the total charging time reached 4 hours.

Subsequently, discharging was performed with a constant current of 2 mA. The discharging operation was completed when the battery voltage reached 3.0 V, and the discharge capacity of the first cycle was measured.

Subsequently, the charging and discharging was repeated for 1,000 cycles under the following conditions: 4.2 V upper voltage limit, 3.0 V lower voltage limit, 2 mA discharge current, and 2 mA charging current. The discharge capacity at that time was then compared to the initial charge capacity, i. H. the capacity at the first cycle, and the capacity retention ratio after 1,000 cycles was calculated. These results are shown in Table 4 below.

(Lithium ion capacitor)

Charge / discharge tests of the lithium-ion capacitor cells were carried out by means of a charge-discharge tester (HJ1001SM8A manufactured by Hokuto Denko Corp.).

Specifically, first, the lithium-ion capacitor cell was charged with a constant current of 2 mA until the cell voltage reached 3.8V. Subsequently, a constant voltage of 3.8V was used for 1 hour to perform a constant current constant voltage charging.

Subsequently, the cell was discharged with a constant current of 2 mA until the cell voltage reached 2.2V.

Then, a continuous charge test was carried out at a cell voltage of 3.8 V and 60 ° C for 10,000 hours. The application of the voltage was stopped after the lapse of 10,000 hours, and the lithium-ion capacitor cell remained at 25 ° C for 10 hours. Then, a charging / discharging cycle of 3.8V-2.2V was performed and the electrostatic capacity was calculated. The Electrostatic capacity per positive electrode material in the first discharge was set as the initial electric capacity (ie, electrostatic capacity per unit weight of the positive electrode), and the ratio of maintaining the electrostatic capacity to the initial electrostatic capacity was determined. These results are shown in Table 5 below. Table 5 Table 3-1 <Electric Double Layer Capacitor> embodiments 2-1 2-2 2-3 2-4 2-5 Positive electrode A B C D H Negative electrode H H H H e Initial electrostatic capacity (F / g) 27.5 30.1 27.9 28.6 27.1 The ratio of capacity retention after 1,000 cycles to the initial capacity (%) 96.2% 94.1% 90.2% 97.7% 94.6% Table 6 Table 3-2 <Electric double-layer capacitor> Compare Beipieles 2-1 2-2 2-3 2-4 2-5 2-6 2-7 Positive electrode H I J K L M H Negative electrode H H H H H H H Initial electrostatic capacity (F / g) 26.1 43.2 26.0 26.1 26.8 26.2 22.7 The ratio of capacity retention after 1,000 cycles to the initial capacity (%) 62.9% 65.7% 70.4% 78.3% 68.5% 76.5% 64.8% Table 7 Table 4 <Lithium Ion Secondary Battery> embodiments Comparative Examples 3-1 3-2 3-1 3-2 Positive electrode Lithium cobaltate Lithium cobaltate Negative electrode F G N O Initial electrostatic capacity (mAh / g) 157 155 158 155 The ratio of capacity retention after 1,000 cycles to the initial capacity (%) 90.0% 90.5% 71.5% 79.3% Table 8 Table 5 <Lithium Ion Capacitor> embodiments Comparative Examples 4-1 4-2 4-3 4-1 Positive electrode A H A H Negative electrode N F F N Initial electrostatic capacity (F / g) 63.4 59.1 60.2 60.2 The ratio of capacity retention after 10,000 cycles to the initial capacity (%) 93.1% 91.5% 97.3% 70.6%

Based on the results shown in Tables 1 to 5, the ratio of capacity retention when using the composites 8 to 12 (each evaluation electrodes I to M), which is the conductive polymer content condition and / or the peak area ratio condition in the XPS. Spectrum not satisfied, compared to the cases in which activated carbon was used (evaluation electrode H) larger (Comparative Examples 2-1 to 2-6). Further, although the ratio of capacity retention became larger compared with that in the case of using graphite (evaluation electrode N), the ratio of capacity retention when using composite material 13 (evaluation electrode 0) was less than or equal to about 80% in both cases (Comparative Example 3). 1 to 3-2). In addition, the ratio of capacity retention was less than or equal to about 80% even when activated carbon (evaluation electrode H) and graphite (evaluation electrode N) were used (Comparative Example 4-1). In addition, it was found that when aniline (electropolymerizable additive) was added as in Patent Document 4, there was almost no improvement in the capacity retention ratio (Comparative Example 2-7).

On the other hand, composites 1 to 7 (evaluation electrodes A to G, respectively) in which a nitrogen atom-containing conductive polymer specific gravity was compounded with the porous carbon material and in which the peak area ratio (nitrogen to carbon ratio) of the nitrogen atoms and carbon atoms in the XPS system were used. Spectrum was in the specified range, the ratio of the capacity retention relative to the initial capacity was greater than or equal to 90%, and the cycle characteristics were classified as excellent (embodiments 2-1 to 2-5, 3-1, 3-2 and 4-1 to 4 -3).

Claims (8)

A composite formed by composing 0.5 to 5 mass parts of a conductive polymer having nitrogen atoms per 100 mass parts of a porous carbon material, wherein a ratio of the peak area of the nitrogen atoms to the peak area of the carbon atoms (nitrogen / carbon ratio) in X-ray photoelectron spectroscopy Spectrum of 0.005 to 0.05. The composite of claim 1, wherein the number average molecular weight of the conductive polymer is from 2,000 to 20,000. The composite according to claim 1 or 2, wherein the conductive polymer is at least one selected from the group consisting of polyaniline, polypyrrole, polypridine, polyquinoline, polythiazole, polyquinoxaline and derivatives thereof. A composite according to any one of claims 1 to 3, wherein the porous carbon material is activated carbon and / or graphite. An electrode material comprising the composite material according to any one of claims 1 to 4. An electric double layer capacitor comprising a polarizable electrode using the electrode material described in claim 5. A lithium ion secondary battery comprising a negative electrode of the electrode material described in claim 5. A lithium-ion capacitor comprising a positive electrode and / or a negative electrode of the electrode material described in claim 5.